On June 24, 2009, the U.S. Environmental Protection Agency (EPA) promulgated significant new use rules (SNURs) for 23 chemical substances, including certain single- and multi-walled carbon nanotubes (CNTs). 74 Fed. Reg. 29,982. The SNURs impose restrictions on the use of only those CNTs that were the subject of two recent premanufacture notifications (PMNs) and consent orders issued under the Toxic Substances Control Act (TSCA).

EPA's announcement has caused some confusion that these SNURs to apply to all single- and multi-walled CNTs. In reality, the SNURs apply only to the particular chemical formulations of single- and multi-walled CNTs that were identified confidentially in their respective PMN submissions. The confusion may stem, in part, from the generic names used to describe the CNT products in the Federal Register notice. TSCA allows a manufacturer to protect its confidential chemical information by using a generic chemical name that does not reveal detailed information about the substance's chemical identity. In this case, EPA allowed use of the generic names "single-walled carbon nanotubes" and "multi-walled carbon nanotubes" in the SNURs. 74 Fed. Reg. 29,990-29,991. More properly, the singular "single-walled carbon nanotube" and "multi-walled carbon nanotube" should have been used.

By way of background, a manufacturer or importer of a "new chemical" (any substance not listed on the TSCA Chemical Substances Inventory) is required under section 5(a)(1) of TSCA to either file with EPA a PMN at least 90 days prior to manufacture or import, or to meet the terms of an exemption or exclusion from the PMN requirements. Here, PMNs were submitted for single- and multi-walled CNT products. The identity of the PMN submitter remains confidential, but according to Porter Wright Morris & Arthur's Nanotechnology Law Report, the submitter is Thomas Swan & Co. Ltd. See EPA Issues Significant New Use Rules for Multi-Walled and Single-Walled Carbon Nanotubes, available here.

The SNURs are based on consent orders issued under section 5(e) of TSCA that restricted the use of these single-walled CNTs (identified by PMN number P–08–328) and multi-walled CNTs (PMN number P–08–177). Because the restrictions in the consent orders are binding only on the submitter, EPA issued SNURs under section 5(a)(2) of TSCA that impose the same use restrictions on all other manufacturers and importers for these same, specific single- and multi-walled CNTs that were notified in P–08–328 and P–08–177, respectively. 74 Fed. Reg. 29,982. Any use of these single- or multi- walled CNTs that does not comply with the requirements under the SNURs is considered a significant new use and requires submission of a Significant New Use Notice (SNUN) 90 days prior to manufacture. The SNURs are codified at 40 C.F.R. part 721.10155 for the specific multi-walled CNTs, and 40 C.F.R. part 721.10156 for the specific single-walled CNTs. Comments on the SNURs must be submitted by July 24, 2009.

For more information on SNURs for nanomaterials, please see our previous articles entitled EPA Issues Significant New Use Rule (SNUR) for Two Nanomaterials, available here, and EPA's Oct 31 Announcement on CNTs, Coupled with Known Parameters for Review, Will Promote the Development of a US-Based Industry, available here.